Root Servers

The authoritative name servers that serve the DNS root zone, commonly known as the “root servers”, are a network
of hundreds of servers in many countries around the world. They are configured in the DNS root zone as 13 named
authorities, as follows.

List of Root Servers

Hostname

IP Addresses

Manager

a.root-servers.net

198.41.0.4, 2001:503:ba3e::2:30

VeriSign, Inc.

b.root-servers.net

192.228.79.201, 2001:500:84::b

University of Southern California (ISI)

c.root-servers.net

192.33.4.12, 2001:500:2::c

Cogent Communications

d.root-servers.net

199.7.91.13, 2001:500:2d::d

University of Maryland

e.root-servers.net

192.203.230.10

NASA (Ames Research Center)

f.root-servers.net

192.5.5.241, 2001:500:2f::f

Internet Systems Consortium, Inc.

g.root-servers.net

192.112.36.4

US Department of Defence (NIC)

h.root-servers.net

128.63.2.53, 2001:500:1::803f:235

US Army (Research Lab)

i.root-servers.net

192.36.148.17, 2001:7fe::53

Netnod

j.root-servers.net

192.58.128.30, 2001:503:c27::2:30

VeriSign, Inc.

k.root-servers.net

193.0.14.129, 2001:7fd::1

RIPE NCC

l.root-servers.net

199.7.83.42, 2001:500:3::42

ICANN

m.root-servers.net

202.12.27.33, 2001:dc3::35

WIDE Project

Configuring the Root Servers

Operators who manage a DNS recursive resolver typically need to configure a “root hints file”. This file
contains the names and IP addresses of the root servers, so the software can bootstrap the DNS resolution process.
For many pieces of software, this list comes built into the software.

More information

ICANN's Root Server System Advisory Council, which is comprised of the organisations that manage root servers, maintains a website with more information on root server operations. This site tracks the locations of the many root servers, and also provides links to individual operators — some of which provide statistics on root server utilisation.